HFC networks are used to deliver cable TV services and high speed data services. A cable TV distribution system generally collects commercial programming from large “off air” TV antennas, a satellite receiving station, or locally originated signals and then distributes these signals to individual subscribers via HFC networks. The collected signals are processed in the headend, then combined and routed to form a serving signal to the subscriber through fiber and feeder paths of the distribution system.
The signal travels along the feeder cable until it reaches the location of the first subscriber (or subscribers). At this point, it is necessary to tap off signals from the feeder cable so that it can be delivered to the subscriber(s) residence.
FIG. 1a shows schematically an inner structure of a conventional tap-off, and FIG. 1b shows a connecting structure of conventional tap-offs.
Common prior art tap-offs are for four, eight or sixteen subscribers. The tap-off shown in FIG. 1a is for eight subscribers. The tap-off includes an input terminal 10 to which signals from a service provider are inputted through a feeder cable 15, an output terminal 20 from which the signals are outputted, AC/RF (Alternating Current/Radio Frequency) parts P1 and P2, a directional coupler DC, seven distributors D1 to D7, and eight bridges BR1 to BR8, where each bridge is connected to a drop cable (not shown) that provides the signal to a subscriber.
The signal level required at the bridge is dictated by the signal level input requirements of the subscriber, as determined by the number of TV receiver devices or the like that are to be connected to the system and the distance between the tap-off and the subscriber.
For multiple dwelling units such as apartment buildings, two or more tap-offs are connected in series by a coaxial cable 5, as shown in FIG. 1b, and signal levels tend to diminish as the signal propagates away from the transmission source. Thus, connecting a plurality of tap-offs in series diminishes the signal quality received by the subscriber further downstream.
The problem that exists in the art is that if one of the tap-offs for the multiple dwelling unit fails, it must be replaced or serviced which results in disruption of the signal and cable service for all remaining subscribers farther down the cable and away from the headend.
In addition, cable handling becomes more complicated and burdensome for the service technician due to the physical interconnection of the plurality of tap-offs.